package cn.tedu.boot02.controller;

import cn.tedu.boot02.entity.Product;
import cn.tedu.boot02.utils.DBUtil;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

@RestController
public class ProductController {
    @RequestMapping("/insert")
    public String insert(Product product) {
        System.out.println("product = " + product);

        try (Connection conn = DBUtil.getConnection()) {
            String sql = "INSERT INTO product VALUES(NULL,?,?,?)";
            //创建执行SQL语句的对象
            PreparedStatement ps = conn.prepareStatement(sql);
            //替换掉里面的
            ps.setString(1, product.getTitle());
            ps.setDouble(2, product.getPrice());
            ps.setInt(3, product.getNum());
            //执行SQL语句
            ps.executeUpdate();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return "添加完成<a href='/'>返回首页</a>";
    }

    @RequestMapping("/select")
    public String select() {
        //创建集合用来装查询到的所有商品对象
        ArrayList<Product> list = new ArrayList<>();
        try (Connection conn = DBUtil.getConnection();) {
            String sql = "SELECT * FROM product";//准备查询的SQL语句 id,title,price,num
            //创建执行SQL语句的对象
            PreparedStatement ps = conn.prepareStatement(sql);
            //执行查询SQL,得到结果集对象
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                Product product = new Product();
                product.setId(rs.getInt("id"));
                product.setTitle(rs.getString("title"));
                product.setPrice(rs.getDouble("price"));
                product.setNum(rs.getInt("num"));
                //把对象装进集合
                list.add(product);
            }
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }

        //把查询到的商品数据装进一个表格标签里
        String html = "<table border=1>";
        html += "<caption>商品列表</caption>";
        html += "<tr><th>id</th><th>标题</th><th>价格</th><th>库存</th><th>操作</th></tr>";
        for (Product p:list){
            html+="<tr>";
            html+="<td>"+p.getId()+"</td>";
            html+="<td>"+p.getTitle()+"</td>";
            html+="<td>"+p.getPrice()+"</td>";
            html+="<td>"+p.getNum()+"</td>";
            html+="<td><a href='/delete?id="+p.getId()+"'>删除</a></td>";
            html+="</tr>";
        }
        html+="</table>";
        return html;
    }

    @RequestMapping("/delete")
    public String delete(int id){
        System.out.println("id = " + id);
        try (Connection conn = DBUtil.getConnection()){
            String sql = "DELETE FROM product WHERE id=?";
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1,id);
            ps.executeUpdate();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return "删除成功!<a href='/select'>返回列表页面</a>";
    }


    @RequestMapping("/update")
    public String update(Product product){
        try (Connection conn = DBUtil.getConnection()){
            String sql = "UPDATE product SET title=?,price=?,num=? WHERE id=?";
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setString(1,product.getTitle());
            ps.setDouble(2,product.getPrice());
            ps.setInt(3,product.getNum());
            ps.setInt(4,product.getId());
            ps.executeUpdate();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return "修改完成!<a href='/select'>返回列表页面</a>";
    }

}
